(RNN) - More than 5 million people have signed up for Obamacare through state and federal exchanges according to administration numbers released on March 18. The new total indicated a surge of about a million in the first two weeks of March.

The first few days of March were the busiest since December, said Marilyn Tavenner, who is the Administrator for the U.S. Centers for Medicare and Medicaid Services in a statement accompanying the release of the numbers. About 1.2 million people signed up in December.

The recent increase came on the heels of a lackluster February, which saw only about 950,000 enrollees, bringing the total then to 4.2 million.

The February lull led to a much-referenced report from Avalere Health, an insurance industry consultant that projected the final enrollment number would be 5.4 million, short of the unofficial goal of 6 million.

The new numbers indicate total enrollment could reach the 6 million target that the nonpartisan Congressional Budget Office projected would enroll by the March 31 deadline. The administration's original goal was 7 million, but the CBO revised its estimate downward after the disastrous rollout of Healthcare.gov in October.

The administration has begun a push to attract younger enrollees, highlighted by President Barack Obama's appearance onBetween Two Ferns, the web-based comedy show starring comedian Zach Galifianakis to discuss the Affordable Care Act. Improvements in Healthcare.gov have probably helped, as well.

The federally run exchange is now working better than some of the state-based exchanges, according to a statement from Avalere CEO Dan Mendelson in the original report. An administration official told Reuters that Healthcare.gov had a million visitors over the second weekend in March.

The administration did not say how many of the enrollees are in the 18 to 34 age range. Young, healthy enrollees are important to keep the Affordable Care Act's premiums affordable by offsetting the costs of older people who require more care.

Also uncertain was how many had paid the first month's premium, which begins actual coverage, and if those enrolled previously did not have insurance. Creating a federally subsidized market of previously uninsured people was also a selling point of the president's signature legislation.

Health and Human Services Secretary Kathleen Sebelius told Congress earlier this month that the administration would not extend the deadline.

Those who have not enrolled by the deadline will be subject to tax penalties.